Does MK-677 Affect Fertility?

In this article, we will closely examine the potential impact of MK-677 on fertility. We will understand the role of growth hormones in female and male reproductive health and how MK-677, a nonpeptide growth hormone secretagogue, might influence this. Although the direct evidence for MK-677 is lacking, we use our neurobiology understanding to extrapolate the existing evidence linking growth hormone and fertility, bringing the science closer to you.
Klara Hatinova

Klara Hatinova

Klara is postgraduate researcher in experimental psychology at the
University of Oxford.

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What is Fertility?

The first step to understanding whether MK-677 impacts fertility is understanding what fertility is.

What is fertility?

Fertility is a term that refers to the ability to conceive and produce offspring.

Fertility is a critical biological function that matures during teenage years and has evolutionary significance. It is primarily regulated by sex hormones, which are released from the gonads or sex organs and the hypothalamus [1]. Fertility is tightly linked to conceiving, whereas fecundity is linked to the ability to give birth to offspring. This distinction is important, as fecundity also includes factors influencing gestation (pregnancy) and birth [2, 3].

Fertility is affected by many factors, including diet, energetic availability and psychological factors [4, 5, 6]. Fertility is also influenced by various factors, including age, exposure to sexually transmitted diseases, or episodic factors, such as frequency of intercourse or timing of coitus [7].

It is not solely a female concern. Maybe unsurprisingly, fertility is an egalitarian issue – about 50% of the fertility dysfunction can be attributed to the male reproductive tract [8].

Understanding fertility is fundamental to understanding whether MK-677 will affect your fertility and inform your decision about whether to take MK-677.

What is MK-677?

MK-677, known as Ibutamoren Mesylate, is an orally active, nonpeptide growth hormone secretagogue. It has been developed to stimulate the secretion of human growth hormone (hGH) , harnessing your body’s natural growth hormone production. This method of increasing hGH levels reduces some of the side effects of synthetic growth hormone.


MK-677 is not FDA-approved and is a banned doping substance in competitive sports.

Although MK-677 is banned in sports, it is widely available to purchase online as a 'supplement' product [9]. MK-677 is also a ghrelin mimetic, which means it mimics the action of ghrelin, a hormone that regulates hunger and growth hormone release [10]. This makes it popular in muscle-building settings, as it can increase lean muscle definition.

MK-677 has been studied for its potential to supplement growth hormone in growth hormone deficiency conditions or muscle wasting, such as in chemotherapy patients, bed-ridden individuals, or people with natural ageing [11, 12, 10].

MK-677 and Sex Hormones

There has been limited evidence about how MK-677 affects female reproductive hormones. This may be because anabolic supplements are generally better studied and more commonly taken by men. Therefore, there is not sufficient evidence to answer exactly how MK-677 affects estrogen and progesterone levels, as the provided studies do not directly address these hormones. However, one study does provide some insight into the impact of MK-677 on luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, albeit in obese males. These hormones are crucial for the regulation of the reproductive system, with LH stimulating the production of sex hormones and FSH being important for sperm and egg production.

In a study involving 24 healthy obese males, it was found that MK-677 treatment did not significantly alter the peak serum values of LH and FSH. The fact that MK-677 did not significantly change these hormone levels suggests that it may not have a major impact on the reproductive hormone system [13]. Nonetheless, it is critical to investigate the impact of MK-677 on female reproductive health.

MK-677 and Bone Health

You may be wondering what bone health has to do with fertility. A lot!

Estrogen is critical for increasing bone strength; therefore, bone strength naturally declines after menopause, which can be problematic. MK-677, an anabolic supplement, improved bone mineral density in postmenopausal women. Although this study does not directly address fertility, it demonstrates that MK-677 can replace some of the anabolic roles of female sex hormones after menopause [14]. This role complements the common use of MK-677 to increase muscle growth and maintain lean body mass in ageing adults, highlighting the specific impact on post-menopausal women.

Growth Hormone and Fertility

Growth hormone (GH), or human Growth Hormone, plays a significant role in human fertility, which means that MK-677 also has similar potential to affect fertility. This is because MK-677 stimulates the release of Growth Hormone and Insulin-like Growth Factor (IGF-1)

Growth Hormone in Women

It's involved in various reproductive processes, including the production of sex hormones, follicle formation, and post-fertilization development, for example, maturation and growth of the oocyte – the fertilised female egg cell [15]. The effects of GH on follicle formation include the promotion of IGF-1 synthesis by the maturing follicle, increasing FSH levels, and, thereby, female sex hormones [16].

GH's effects on fertility are particularly noticeable in women with growth hormone deficiency. In a case study, a woman with GH deficiency underwent two in vitro fertilization (IVF) procedures. The first, without GH treatment, did not result in pregnancy. However, after three months of GH administration, the second IVF procedure led to a successful pregnancy and the birth of a healthy boy. This suggests that adequate levels of GH are essential for the competence of the oocytes in infertile patients with GH deficiency [17].

insulin-like. GH supplementation may also improve fertility outcomes in women over 40. In a study involving 100 women over 40 undergoing assisted reproduction treatment, those who received GH had higher per-transfer clinical pregnancy (19.9% vs. 9.9%) and implantation (11.2% vs. 5.2%) rates [18].

However, the role of GH in fertility is not fully understood, and its effects can vary. Some studies have shown improvements in oocyte yield, enhanced embryo quality, and increased live births, while older studies have found no significant effects [19, 20]. Therefore, while GH can potentially enhance fertility, the effect is more prominent in people who have insufficient GH to begin with. This means that you must consult a healthcare professional about your GH levels before considering taking MK-677 to improve your fertility.

Growth Hormone / MK-677 and Sperm Count

Similar to the effects of human growth hormones on female fertility, the benefits of human growth hormones and increased IGF-1 levels have been found in sperm count, sperm quality and testosterone levels [21].

Insufficient growth hormone, for example, in hypogonadal men, is associated with lower fertility. Reduced fertility was found to be restored in men taking growth hormone supplements. This suggests that mk-677 could improve fertility in hypogonadal men and men with low sperm count. However, side effects on metabolism, blood pressure, and body composition, such as total fat mass and lean body mass, should be monitored to avoid the deleterious impact of MK-677 on male health.

Did you know?

$AMK-677 has not been linked to brain damage!can-mk-677-cause-brain-damageA$. Quite the opposite, MK-677 can improve certain cognitive functions in humans.

Summary: Does MK-677 Affect Fertility?

Based on the information available, no direct evidence suggests that supplementing with MK-677 impacts fertility. However, there is sufficient evidence that human growth hormones affect fertility and embryo development. Therefore, increasing your hGH levels by supplementing MK-677 will impact your fertility. Whether the positive or negative effect depends on your pre-existing hGH levels, as benefits were primarily found in people with insufficient hGH.

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Klara Hatinova

Klara Hatinova

Klara is a postgraduate researcher in experimental psychology at the University of Oxford. She has worked across a spectrum of hot topics in neuroscience, including her current project measuring reinforcement learning strategies in Parkinson’s disease. Previously, she studied the efficacy of psilocybin as a therapy for critical mental health conditions and examined molecular circadian rhythms of migraine disorders. She completed her undergraduate degree in Neuroscience at the University of Glasgow and participated in a year abroad at the University of California, where she worked on a clinical trial for spinal cord injury.